1. Field of the Invention
An embodiment of the present invention relates to an oxide semiconductor film. In addition, an embodiment of the present invention relates to a semiconductor device.
It is to be noted that the semiconductor device in this specification refers to all devices that can function by utilizing semiconductor characteristics, and electro-optic devices, semiconductor circuits, and electronic appliances are all semiconductor devices.
2. Description of the Related Art
In recent years, development of semiconductor devices formed using field-effect transistors including oxide semiconductor films has been advanced. The oxide semiconductor film has a function as a layer in which a channel of the field-effect transistor is formed (also referred to as a channel formation layer).
As the field-effect transistor, for example, there are a field-effect transistor in which an oxide semiconductor layer formed with an oxide semiconductor film containing indium (In), gallium (Ga), and zinc (Zn) is used as a channel formation layer, a field-effect transistor in which an oxide semiconductor layer formed with an oxide semiconductor film containing indium (In), tin (Sn), and zinc (Zn) is used as a channel formation layer, and the like (e.g., Patent Document 1).